Tor Vergata Synoptic Solar Telescope: spectral characterization of potassium KI D1 MOFs

Synoptic telescopes are fundamental tools in Solar Physics and Space Weather. Their typical high cadence full-disk observations are pivotal to assess the physical conditions on the Sun and to forecast the evolution in time of those conditions. The TSST (Tor vergata Synoptic Solar Telescope) is a synoptic telescope composed of two main full-disk instruments: an H-alpha Daystar SR-127 telescope and a Magneto Optical Filter (MOF)-based telescope in the Potassium KI at 769.90 nm. The MOF consists in a glass cell containing a Potassium vapor where a longitudinal magnetic field is applied. The MOF-based channel produces full disk Line-of-Sight magnetic field and velocity maps of the solar photosphere at 300 km above the solar surface. In this work, we present the optical setup, the spectral characterization of the MOF-based telescope, and details on the spectral characterization of the MOFs cells which is a required test to obtain calibrated magnetograms and dopplergrams.